It can't be 90%.
Firstly it's not the same as the baby twins that was separately the last time.
And it's mentioned it's the 1st time this is being done in the world.
Since it's the 1st time, there are bound to be things unexpected.
I think it's the media hype and all the attention, that makes us (the viewers) think or assume the operation sure succeed.
(too much pressure on the medical team)
Any way, just as it was brave for the twins to come forward and do the surgury despite the chances of dying.
I think the medical team was also very brave to try to do something that was never attempted in history.
Imagine, if it fails, there may be people who put the blame on them.
Still, I believed the medical team must be very disappointed as all the effort and months of planning and the 57 hours of surgury has not had a positive outcome.
what the heck. Life is so unfair.